1This target is only valid in the 2.B nat 3table, in the 4.B PREROUTING 5and 6.B OUTPUT 7chains, and user-defined chains which are only called from those 8chains. It redirects the packet to the machine itself by changing the 9destination IP to the primary address of the incoming interface 10(locally-generated packets are mapped to the localhost address, 11127.0.0.1 for IPv4 and ::1 for IPv6). 12.TP 13\fB\-\-to\-ports\fP \fIport\fP[\fB\-\fP\fIport\fP] 14This specifies a destination port or range of ports to use: without 15this, the destination port is never altered. This is only valid 16if the rule also specifies one of the following protocols: 17\fBtcp\fP, \fBudp\fP, \fBdccp\fP or \fBsctp\fP. 18.TP 19\fB\-\-random\fP 20If option 21\fB\-\-random\fP 22is used then port mapping will be randomized (kernel >= 2.6.22). 23.TP 24IPv6 support available starting Linux kernels >= 3.7. 25